Cam lapping machine



Aug. 31, 1948. H. s. INDGE CAM LAPPING MACHINE 3 Sheets-Sheet 1 Filed July 50, 1946 INJJ'GE Aug. 31, 1948. H. s. INDGE 2,448,146

l CAM LAPPING MACHINE l Filed July so, 194e s sheets-sheet 2 HERBERT 5'-, INDGE aw A Aug. 3l, 1948.

Filed July .'50, 1946 H. s. INDGE. 2,448,146

CAM LAPPING MACHINE 3 Sheets-Sheet 3 HERBERT 5. INJJGE:

Patented Aug. 31, 1948 CAM LAPPING MACHINE Herbert S. Indge, fWestboro, Mass., assignor to Norton Company, Worcester, Mass., a. corporation of Massachusetts Application July 30, 1946, Serial'No. 687,100'

16 Claims.

The invention relates to lapping machines, and more particularly to a'machine for lapping a plurality of cams on a cam shaft.

One object of the invention is to provide a simple and thoroughly practical cam lapping machine. Another object of the invention is to provide a cam shaft lapping machine in which the table for supporting the cam shaft and master cam shaft is supported for a relatively short reciprocatory stroke by means of flexible rubber bearings which permit a lswinging movement of the table so as to eliminate friction and wear between metallic parts, and also to eliminate the necessity of lubrication.. Another objectof the invention is to provide a cam lapping machine Ycovering a longitudinallly reciprocable table which is provided with a positively rotated'spindle and center to support acam shaft to be lapped,

and a second parallel spindle and center to support a master cam shaft parallelto the camshaft beingground. A further object of the invention is toy provide such a cam .lapping machine with a motor f driven driving .mechanism which is .ar-

ranged synchronously to rotate both the work..

supporting and themaster cam shaft supporting spindles. Y f

A further objectV f the invention is to provide pivotally, mounted, lapping armsv which are arranged for atIanSVerseand longitudinal swinging or rocking movement on non-wearing frictionless bearing supportsl so as to eliminate wear and the necessity of lubrication. Another object of the invention is to -provider downwardly projecting substantially verticalY lapping arms and .35

follower arms for each'of the cams to be lapped,

in which the entire lapping arms asssembly is arranged for a longitudinal swinging movement which is also supported by flexible rubber bearings to eliminate wear and lubriation.[Another object ofthe invention is to provide a cam lapping machine in which the master cam' shaft is identical with a finished lap cam shaft. Other objects will be in part obvious, or in part pointed fout hereinafter. y g i The invention accordingly consists in the features of construction, combinations of elements, andvarrangement of parts, as will beexemplied vin thev structure to be hereinafter described',` and the scope ofthe application of which indicated in the following claims. Y

Inthe .accompanying drawings, -in which is shown one vof various possible `embodimentspf the mechanical features ofthe inventionz' Fig. l is a front elevation ofA cam lapping willfbe -machinezembodying this, inventiomiff' Fig.- 2 is a fragmentary plan view ofthemachine showing the foot stock;

Fig. 3 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 3-3 of Fig. 1, showing the connection for transmitting a longitudinal reciprocatory movement to the lapping arms;

Fig. 4 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 4-4 cf Fig. 1, showing the spindle driving mechanism and the table guiding mechanism;

Fig. 5 is a longitudinal sectional view, on an enlarged scale, taken approximately on the line 5--5 of'Fig. 1, showing the arrangement'of the cam shaft driving and the master cam shaft driving spindles;

Fig. 6/is a fragmentary sectional view, taken approximately on the line 6--6 of Fig. 5, showing the driver forrthe master cam shaft;

Fig. 7 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 1-1 yof Fig. 1; Y

Fig. 8 is a vertical sectional View taken approximately on the line 8-8 of Fig. 7, showing a portion of vthe table reciprocating mechanism;

Fig. 9 is a diagrammatic end elevation of one of the exible rubber bearings,v on an enlarged scale;

Fig. /10 is a similar diagrammatic View of the bearing, illustrating how the rubber yields when the outer periphery of the bearing is oscillated in a counterclockwise direction;

Fig.` 11 is a similar diagrammatic view ofthe bearing, showing how the rubber yields as the outer periphery of the bearing is moved in a clockwise direction;

Fig. 12 is a vertical sectionalview on an enlarged scale, taken approximately on the line I2-I2 of'Fig. '1, showing the driving mechanism for imparting a longitudinal reciprocatory stroke to-"the lapping arms;

Fig. 13 is a sectional view partly in elevation, on an enlarged scale, taken approximately on the linefl3-I3 of Fig. 1, showing one of the pivotal supports for the lapping arm assembly;

Fig. 14 is a right-hand elevation on an enlarged scale, taken approximately on the line I4--l4 of Fig. 1,'showing one of the lapping arms and follower arms, partly broken away and shown in section, to more clearly illustrate the construction;

Fig. -15 is a horizontal sectional view, taken approximately on the line I5-l5 of Fig. 14 through the guide for the lapping and follower Y arms;

master cam shaft 48. Ythe .master cam shaft is, supported by an aligned foot stock centerv so that the mastercam shaft is arranged and supported parallelwto the. camA .shaft to be lapped.

through the connecting link which connects the lapping arm with the follower arm; and

Fig. 17 is a fragmentary detail view of a portion of a modified form of the lapping arm adapted for use with iiexible abrasive paper or cloth instead of a bonded abrasive element, as shown in Fig. 14.

A cam lapping machine has been illustrated in the drawings comprising a base 20, which supports a .longitudinally movable table 2|. The table 2l is provided with a head stock 22 and a foot stock 23. The head stock 22 is provided with a Work rotating spindle 24, which is supported in anti-friction bearings 25 and 26 in the frame of the head stock 22. :Thesprldlelids provided with a work driving head- 21,..whichis provided with means including a driving key 27a (Which is arranged) to support androtatef-the left-hand end of a cam shaft 2B. The other end of the cam shaft 28 is supported by afoot stock center 29, which is carried by the foot stock 23.

A suitable driving `mechanism is provided for rotating the spindle 24 andthe cam shaft V23 comjprising an electric mctor 3|l,which is mounted within the base 2il of the machine on a pivotally .rncunted platen 3L ,suppcrtedon a rock shaft 32,` which is in turn The platen 3| is pivotally supported by the base 2S. An adjusting screw 33 is provided .for pivotally adjusting the platen 3l so that the position of the motor Sii may be varied as l.desired -to provide the desired driving tension` on the driving belt, to be hereinafter described. Ihe Vmotor 3U is provided with armultiple V-groove pulley- 34 which is connectedby multiple V-belts with amultiple V-groove pulley 36 which is supv ported on a rotatable shaft 31.

The shaft 31 is supported in anti-friction bearings 38 and 39 carried by the head stock 22. A driving worm 4U iskeyed to theshaft 31 and, meshes vwith a worm gear 4| which is keyed Qn thework spindle 24. l It will, be readily apparent fromwthe foregoing-disclosure that rotary motionof `the Lmotor, pulley 34 will be transmitted through the driving Lmecha- 4 nism just described, to impart a rotary motion ,tothe-spindle24 andthe cam shaft 28.

A second spindle 145 is supported in antifriction bearings` 45 and 41 carried by vthe head stock 2 2. The spindle 45 is arranged parallel to thehead stock spindle 24, and serves to. Support and-rcgtate one end of a master cam shaft. 'The spindle-45 is p r )v i ded k with a driving head 48,"-

which drivingly engages the left-hand end of a The hand-hand end of in order to A time the master, cam .shaft 49 relative to the cam -shaft28, a suitable4 adjusting mechanism is vprovided for the `mastercamshaft driver 48, which is illustrated in Fig. 6. The* driver 48 is supported on a flangedv support 48a.

'ljhe driver 48 isprovided with a plurality ofV symmetrically arranged elongated slots 48h. Clamping screws 4to pass through the elongated slots 48D and are screw threaded into the flangedv member 48a. It Iwill be readily apparent'that the driver 4B maybe rotarily adjusted `relative vto the flanged member 48 by means of the clamping screws 48o. In Vorder to facilitate this adjustment, the anged member 48d is provided with a `projecting lugwfid and the driver 4 8 is provided wit h a pair of opposed aligned adjusting vscrews 48e and 43,1c which serve as push and pull screws .to facilitate a precise adjustment of the driver 48 relative to theiianged membra.

15, a gear 54.

75 layery pff-,iiexible rubber: `l l.

When a relatively long cam shaft having a plurality o-f cams to be lapped is mounted in the machine, it is desirable to support the cam shaft and also the master cam shaft midway between the drivers and the foot stock centers by a steadyrest 5l This steadyrest has not been illustrated in detail, since any conventional steadyrest which is wel-l known inthe art may beutilized.

,In order-thatthe mastercam shaft spindle 45 l0 may be synchronously rotated with the head stock spindle 24, a suitable driving connection is providedcomprising a gear 52, which is keyed on the head stock spindle 24. The gear 52 meshes with anidlergear53, which in turn meshes with Thegear 54 is keyed to the master cam shaft spindle 45. In order to take up back v,lash in the gearing above described, the idler gear 53 is preferably formed as a split gear so that one V.part thereof may be adjusted relative to the other to compensate for baek lash between the gear teeth. l lnvorder tofattain one of theobjects-of this invention, it isdesirable to provide a support for the work table I I whereby the tableemay be moved longitudinallyina substantially` rectilinear path, without the necessity of overcoming the friction between the .commonfand well known tableways. In a cam lapping machineof the present type. it is desirableto reciprocate the worksupport longitudinally through a relatively short stroke, which in the average caseis not over 1/8 to 1% of an inch in length, in order to5provide theA desired vbreakup motion between the rotating cam to be lapped vand the'lappingelement. InV thepremay rbe swung in ya longitudinalA directiom, thus v eliminating the usual friction andwear of table .ways and also eliminating the necessity .for .pro- -49 viding lubrication-therefor. vAs illustrated inthe drawings, the base V2li is provided 4with a pair `of upwardly. extendingv brackets 60. andf 6| at the nOppositeends thereof. Theibrackets and 6i support `pivot shafts (i2-and 63. A pair lof downwardly extending substantially vertical parallel rock arms 64 and 65 are supported by -thepivot vshaftsv 62 and 63. These rock arms are arranged in pairs, which are vspaced as shown in, Fig. 4 of the drawings. v The rock arm 64 being arranged adjacent tothe front face of the table and-the rock arm; 64agbeingarrangedin alignment therewith but adjacent to the rear face ofjthe table 2|. A spaced arm is similarly provided at the, rear lof the machine 4in alignment with the rockarm 35. Pivotshafts andr'l pivotally connect the rock arms 64 and 65 with the oppositeiends .of .the table ,2|.v

Inprder to eliminate kthe usual metalfto-metal pivotal connection ,between the rock farms and vthe pivotv shafts, 4iiexible rubber Ybearings areV provided, .which permit.. a rocking movement-of the .arms through the required angular motion. lrIhe flexible bearing is an indestructible unipnof @Qncentric metal cylinders joined by a vlayer of rubber under pressure f or thepurpose cfg,` mounting or couplingmachne parts or equipment .in ,mo- -tQn- .These-fbeerirles depend .upon a ,mechanical adhesion rather.tl 1 an achemicalr bond to obtain efficient Operatiga Asillustrated .diagrammatically in Figs.v 9,y 10 Vand 11,l these bearings comfprise-ari outer metallic cylinder-9 and van inner metallic ylinder 10,; betweenwhichis provided a `These bearings. may

be of the well-known-ftype such as is manufacment to the table 2|.

tured'by the General Tire andRubber Company of Akron, Ohio.

VThebearings are mounted so that the metallic outer and inner cylinders are iixedly mounted to one of the machine parts. When the outer cylinder vis rocked ina counterclockwise direction, the .rubber 'H yields, as indicated by the dotted lines in Fig. 10. Similarly, if the outer metallic cylinder isv movedin a clockwise direction, the rubber layer 1| yields as indicated by the dotted lines in Fig. 11. One of these flexible rubber bearings is interposed between the pivot shafts 62, 63, 66 and 61 and the rock arms 64 and 65. The outer vcylinder 69 of each bearing is fixed relative to the rock arms 64 and 65and the inner cylinder 10 is xed relative to the pivot shafts 62, 63, 66 and 61.

:v It will be readily apparent from the foregoing disclosure that when the table 2| is moved in a ...longitudinal direction, a swinging motion will be imparted through the` rock arms 64 and 65. By this construction a frictionless support is provid- Ved for the-table 2 I, eliminating the standard type ythese links 11 has been illustrated in detail in Fig.

4. The base supports a stud'15 which carries y a flexible rubber bearing 16. The inner part of 'the bearing is xed relative to the stud 15 and the outer part is fixed relative to the link 11. A stud 18 is mounted on the table 2| and serves as a support for a flexible rubber bearing 19. The inner part of the bearing is fixed relative to the stud 18 ,l and the outer part is fixed relative to the link 11.

The arrangement of the link 11d is identical Y with that just described in connection with the 2| may be'moved longitudinally, the links beingf free to swing due to the flexible rubber bearings, which serves to hold the table against transverse movement during its reciproeatory stroke.

A suitable motor driven mechanism may be provided for imparting a reciprocatory move# This mechanism may comprise an electric motor 8| which is connected 'to an integral gear reduction unit 82 to rotate a vertically arranged shaft 83. Ahead 84 (Fig. 8) is mounted on the upper end of the shaft 83 and servesas a support vfor an adjustably ymounted crankpin 85. The crank pin 85 is provided with -a roller 86. A needle bearing is preferably interposed between the crank pin 85 andthe roller 86.

. The roller 86 rides ink a transverselyarranged elongated -slot 81 formed in the under side of the table 2|. In order to facilitate adjustment of the reciprocatory stroke of the table, the crank pin 85 I from the axis of. rotation of the shaft 83 rto increase `or, decreasethejthrow of the crankpin 85as desired.' When themotorxl is started-, a'rotary f'rnotion is imparted through the shaft' 83, the

head y84 to the crank pin 85. The crank pin 85 through the roller 86 transmits a longitudinal reyl()v vping arm 98 is pivotally supported by means of ciprocatory movement to the table 2 In order to simultaneously lap a plurality of cams on the cam shaft 28, a plurality of spaced lapping arms 95, 96, 91 and 98 are provided. These lapping arms are all identical in construction, and consequently only one of these arms has been illustrated in detail in Fig. 14. The lapa stud 99 on a bracket |00. A flexible rubber bearing |0| is interposed between the lapping arm 98 and the pivot stud 99 so as to provide' a frictionlessA bearing which permits the desired rocking movement 0f the lapping arm 98 during alapping operation. The bracket |00 is provided with a clamping block |02 which, together Y with the upper surface of the bracket, forms a dovetailed clamping surface for adjustablsr clamping the bracket |00 in the desired adjusted position on a supporting member.

A lapping block |03 is pivotally supported by a l stud |04 carried by the lapping arm 98. As illustrated in Fig. 14, a cylindrically shaped bonded abrasive lapping element |05 is supported by the block |03 and is arranged to operatively engage the cam 28 to be lapped. A compression spring |06 is carried by the arm 98, and serves to yieldably maintain the lapping element |05 in operative engagement with the cam being lapped during a lapping operation. A stop stud |01 is provided for limiting the swinging movement of the block 03 relative to the lapping arm 98.

A follower arm |08 is pivotally supported by means of a stud |09. A flexible rubber bearing |0 is interposed between the stud |09 and the follower arm |08. An adjustable bracket is adjustably supported on the lower end of the follower arm |08, and serves as a support for a cylindri-cally shaped follower roller H2. The follower roller ||2 is arranged to engage and follow the master cam 49a during rotation thereof. The follower roller |2 is preferably of a diameter equal to the diameter of the lapping element |05.

In order to connect the follower arm |08 with the lapping'arm 98, a connecting link ||3 is provided, which is connected by means of a stud ||4 to the follower arm and by means of a stud I5 to the lapping arm 98. AY transversely extending guide ||6 is mounted on the lower end of the bracket |00. The guide I |6 is provided with slots I|1 and ||1a (Figs. 14 and 15), which serve as guides for the lapping arm 98 and the follower arm |08 during a lapping operation. A tension spring ||8 (Fig. 14) is connected at one end by a stud ||9.with the guide H6 and bracket |00, and at the other end by a stud |20 with the follower f arm |08. The spring ||8 serves to maintain the lthe master cam 49.

, determined contour. l

A modified form of lapping element has been illustrated in Fig. 16, Vcomprising a pivotally mounted block |2| which is pivotally supported block 2| serves as. a support. for a cylindrically shaped member or shoe; |22. A flexible..1bandr |23 .of yieldable material: is' supported :by .the Lblock |22 and wraps around the Y.exposed portion of 4the shoe |22.. Astripiof` flexiblerabrasive.paper If desired, a continuous .roll of abrasive'paper. or cloth may be provided, .as is old and well known i in .the` cam lapping art.

The base .26 is provided'with a pair .'ofkupwardly extending bracketsY |25 and |26, which serve as .a supportfor a llongitudinally extending frame |21. The lowersurfaceof `thel frame |21 is provided with a dovetailed slidewaye'lZ,` which serves in a manner vto be :hereinafter described, to support the mechanism for carrying `thelapping arms.

.The lapping arms 55,36, 91 ahdlg arev preferably arranged in pairs for asimultaneous reciprocatory movement in lopposite directions to impart an additional breakup motionto the lapping operation. A longitudinally movable vsupporting member |35 is Yprovided for supporting the lapping arms 91 and S8, and asimilarsupporting member 53| is provided for. supporting the lapping arms 35 and 96.

A `pair of brackets |32 and l33'are provided with dovetailed lapping surfaces, which aresupported on the dovetailed slideway -iZ on the frame |21. The bracket |32 is pivotallyl .connected by astud |34 with aV rock arm or` frame |35. The lower end of theframe |35 is connected 'by a vstud lll!) with the supporting member |35. The bracket |33 supports apivot stud |52, which in turn pivotally supports the upper end of a rock armor frame |43. A stud. IM'connects the lower end of the frame |43 to theother end of the supporting member |36. Flexible rubber bearings are interposed betweenVv each of the studs |35, MQ, |42 and |M,and the'respective ends of theframes |35 and |3so as to provide frictionless resilient bearingsv so that the supporting member |35 may berreadily moved in a longitudinal direction through the required stroke.

A pair of brackets |45 and ld'areprovided for supporting the supporting member |3 The bracket |45 carries a stud |41, which is pivotally connected to the rock arm or frame |49. A pivot stud connects the lower .end of .the frame |49 with one end of the supportingmember |3i. stud |58, which is ypivotally connectedV with` the rock arm or frame |58. 'The lower end of the arm |59 is connected by means of a stud |52 with the otherl end off the supporting member |3I. A flexible rubber bearing isinterposedbetween each of the studs |1,'|4.8,l5|1and;.|52

and the respective ends of the frames |49 .and

|55, so that the supporting member `|3| may be Similarly7 the bracket |116 carries aV 1 1 -In :order to transmit a i simultaneous ,zrecpre catory movement to the supportingzmembe'rs |30 Aand |3|, amotor. drivenmechanism isrprovided comprising a. motor -;|55, which, is provided .with a motorpulleyl. r The motor. pulley |56. is .con- `nected'bymulti-ple Vebelts .|51 with amultiple V-groovepulley-i 58. .Y .Ther pulley.' |58. is supported .onjone endof a rotatableshaft'l59. The shaft ,and |62, ,which'aresupported by a frame |63.

Thefrarne |63v is adjustably clamped .tozthe bracket |21. Apairof. opposedeccentrics :|64

.and |55 (Fig. '12) arerkeyedtothe shaft |59.

The eccentric..|65;is connected by a .connecting rod |61 with a studi 68. :The swell-68 is carried by a bracket'. |16., whichis .fastened to the rockarm |35. VvSimilarly,:the eccentric |64 isconnected by a connecting rod. |35 with apivot stud |69,which is carried by a lbracket |1 fastened to the rock arm A| 5U.. Itwill be readily. apparent from .the foregoing disclosure thatV when .the motor |55 isstarted, the shaft. |59 will rotate the eccentricsy |64 .and

|55 :and :impart a simultaneous.. reciprocatory movement in yopposite directions `.through the mechanism above 4describedto the supporting members and;|3|, and alsqvto the lapping arms and elements supported thereby. Thereciprocatory'movementv of .thelapping elements isprovided for .a breakup motion, to provide a more efcient lapping action betweenl the lapping `element and the camr being lapped. The reciprocatory stroke .of the; lapping elements is relatively sh'ort,.and preferably doesinot exceed-.1% ofan inch. Therefore, Yeven though a Vswinging motion is provided for the .supporting members IBEByand |3|A due tothe relatively-short stroke,

. these supporting members, .together with .the lap `supported thereby, -zwill;mov.e through a substantially rectilinear'path.

To facilitate ycontrolbf-the electric motors, a ypush button switch |15 isprovided for vcontrolling the workdrive motor 36. A push buttonswitch l|16 is provided `for controlling the table reciprocating motor'l! and a pushbutton switch |11 is 'provided `for controlling the lap .arrnrecip- -rocating motor |55.

It will `thus be seenthat there has been provided bythe .inventionapparatus in which the various objects `hereinabove set forth, .together with many thoroughly practical-advantages, are `successfully achieved. As many possible embodiments may bemade of the -above invention,

and as many changes mightbe made in the embodiments above set forth, itA is to be understood that all-matter hereinbefore set forth or shown in the accompanying drawingsv is to be interpreted as illustrative and not in a limitingsen-se.

' Iclaim:

l. VIn a cam lappingmachine having a, reciprocable table, means to reciprocate said table, a Vheadstock and -footstock on said table, apair'of f rotatable parallel spindles on said "headstock, a

`readily moved or reciprocated in a longitudinal setting up the Vmachine for lapping a, givencam' shaft 28, the brackets |53 .may be adjusted Vlongitudinally on the supporting'members |36 and |3|, so as to align the lapping elementsand follower rollers with the respective cams on the .cam

-1 shaft to be lapped and the master cam shaft;

k'pair of aligned parallel footstock centers on' said footstock rotatably toisupport amaster camshaft and a cam shaft to be lapped inl parallel relai tionship with each other', means to'synchronously rotate said spindles, a, pivotally mounted follower yarm having a lmaster cam follower roller 'which .Y engages a-master cam,` yieldablemeans toemainrmaster cam,v a pivotally mountedlapping arm yhav-ing aiayieldably mounted 'lapping elemententain said roller inoperative engagement with the gageable with a camtogbe lapped, a .guide for f, .said follower. and 'lappingV arms,:andv a link confnectngr` said *armswhereby .a controlled swing- 9 ing movement isl imparted tothe lapping element.

2. In a cam lapping machine having'a reciprocable table, means to reciprocate said table, a headstock and'afootstockvon saidv table, a pair of rotatable parallel spindles on said headstock, a pair of aligned parallel footstock centerson said footstock rotatably to support a master cam shaft and a'cam shaft to be lapped in parallel relationship with each other, means including an electric motor to synchronouslyl rotate said spindles, a pivotally mountedfollower arm having a master cam follower roller which engages a master cam, yieldable means to'maintain said roller inoperative engagement with the master cam, a pivotally mounted lapping arm having a yieldably mounted lapping element engageable with a cam to be lapped, a guide for said follower and'lapplng arms, aV link connecting said arms whereby a controlled swinging movement is imparted to the lapping` element, and means to reciprocate said follower and lapping arms.

3. In a cam lapping machine having a base, a headstock and a footstock, means rotatably to support a cam shaft to be lapped thereon, a. synchronously rotated master cam shaft which is arranged parallel to the cam shaft to be lapped, al longitudinally reciprocable table, spaced pivotally mounted arms to support said-'table sothat it may be -reciprocated longitudinally in a, substantially rectilinear path, means including a motor driven crank pin to reciprocate said table, a pivotally mounted cam lapping arm having a lapping element thereon, a pivotally mounted follower arm having a follower roller thereon which is arranged to engage a master cam, said lapping and follower arms being arranged parallel to each other, a link pivotally connecting said arms so that a controlled swinging movement is transmitted by the follower arm to the lapping arm and element, and yieldable means between said lapping element and lapping varm whereby the lapping element is yieldably maintained in lapping engagement with the cam being lapped during'a lapping operation.

4. In a cam lapping machinehaving a base,

a pair of spacedupwardly extending brackets adpacent to the opposite Vends of the base, a pivotally-mounted pendulum-type arm suspended from each of said brackets, a longitudinally movable table, pivotal connections between the opposite ends of the table and the lower ends of said arms so as to facilitate ar longitudinal reciprocatory Vmovement of the table, a motor driven adjustable pitman to impart a relatively short reciprocatory stroke to said table, a rotatable work support on said table including a pair of parallel synchronously rotated spindles and footstock centers to support a 'cam shaft to be lapped and a .master cam shaft, a pivotally mounted follower arm having a follower roller which Yis arranged to engage ra master cam, a pivotally mounted lapping arm having a lapping element yieldably mounted thereon, operative connections between .sai-d arms, a i supporting member for both of said arms, and means to reciprocate said member to impart a reciprocatory motion to said master cam roller and said lap-` ing element relative to the cam being-lapped.

5. In a cam lapping machine as'claimed in claim 4, in'combination with the parts 'and features therein specified, of a bracket adjustably clamped to the underside of the supporting member, a follower arm pivotally suspended vfrom said'bracket, a follower. roller on said arm to engage a master cam, a lapping arm pivotally suspended to the underside of the supportingmember, said lapping arm being spaced from and substantially parallel to the follower arm, a lapping element yieldably supported adjacent to the lower end of said lapping arm, a `connecting link pivotally connecting both of said arms so that a controlled rocking movement is transmitted by the follower roller to the lapping element, and a guide fixedly mounted on said bracket to guide the swinging movement of said follower and lapping arms.

. 6. In a cam lapping machine having a base, a pair of spaced upwardly extending brackets adjacent to the opposite ends thereof, a pivotallymounted pendulum-type arm suspended from each of said brackets, a longitudinally movable table, pivotal connections between the opposite ends of the table and the lower ends of said arms so as to facilitate a longitudinal reciprocatory movement of the table, a motor driven adjustable pitman to impart a relatively short reciprocatory stroke to said table, a rotatable work support on said table including a pair of parallel synchronously rotated spindles and footstock centers to support a cam shaft having a plurality of cams to be lapped and a master cam shaft having a plurality of master cams, a plurality of spaced pivotallymounted follower arms each having a follower roller which is arranged to engage one of said master cams, a plurality of spaced pivotally mounted lapping arms each having a lapping element yieldably mounted thereon yieldably to engage one of said cams to be lapped, operative connections between said follower and said lapping arms, an .oscillatable supporting member to support said followers and lapping arms, and means to oscillate said member to impart a reciprocatory motion to said master cam rollers and said lapping elements relative tothe cams being lapped.

'7. In a cam lapping machine having a base, a pair of spaced upwardlylextending brackets adjacent to the opposite ends thereof, a pivotallymounted pendulum-type arml suspended from each of said brackets, a longitudinally movable table, pivotal connections between the opposite ends of the table and the lower ends of said arms so as to facilitate a longitudinalv reciprocatory movement of the table,'a motor driven adjustable pitman to impart a relatively short reciprocatory strokeV to said table, a rotatable work support on said table including a pair of parallel synchronously rotated spindles and footstock centers to support a cam shaft having'a plurality of 'cams to -be lapped and a master Acam shaft having a plurality of master cams, a plurality of pivotally mounted follower arms havingA follower rollers which arearranged to engage said master cams, a plurality of Apivotally mounted lapping arms each having a lapping element yieldably mounted thereon yieldably'to engage said camsl able eccentrics, connecting rods to connect'each` 9. In a cam lapping machine asnclaimedin-r claim '7, in combination with `the parts and features thereinv specied, of a pair of spaced pivotally-mounted'-pendulum type arms to support each of said supporting members, a rotatabler drive shaft, a pair of diametrically opposed eccen-` trics onsaid shaft, and connecting rods to connect each ofv said eccentrics with one of said arms to impart-a swingingv motion thereto and thereby to reciprocate said memberssimultaneously in opposite directions.

10. In a cam lapping machine as claimed in claim?, in' combination with the parts and fea,- tures therein specified, of a longitudinal dovetailed slide way formed on the underside of said supporting member, a plurality of spaced depending brackets ladjustably clamped on said dovetailed slide way, a pair. of pivotally mounted downwardly extending parallel arms on each of said brackets, a link pivotally connected adjacent tothe lower'` end of-each of said arms, a follower rollerl adjacent to the lower end of one of said' arms which is arranged to engage a master canna lappingelement yieldably mounted adjacent to the lower end of the-other of said arms, a guide on said bracket to guide both of said arms, andmeans including a spring interposed between said bracketand follower arm to maintain said follower in operative engagement with a master cam so as to impart a controlled movement toA saidV lapping element duringv a lapping operation;

l1. In -a cam lapping machine havinga base, a longitudinally reciprocable table, a rotatable work support including a headstock and a footstock on said table, an antiefriction support forv said table'comprising a pair'of ispaced bracketsV adjacent totheoppositeends of'said base, piv-Y otally supportedsubstantially vertical arms depending from said brackets, flexible rubberbearf ingsinterposed between said brackets and arms, flexible rubber bearings connecting thelower ends of saidarms with the opposite ends of lsaid table, and means to impart a relatively short'reciprocatory stroke to said table, said rubber bearings being suflicientlyrresilient so that the arms maybe rocked relative to the bracketsand table duringreciprocation of 'fthe table.

12: In a cam lapping machine asrclaimed in claim 11, in combination with the .partsand fea'- tures therein specified, of a frame, a reciprocable supporting member, a pairof pivotally mounted rock arms to'support said member, flexible rubber bearings connecting said rock arms with said frame, flexible rubber bearings connecting the'V lower ends of said arms with the' opposite ends of said supporting member, means to reciprocatet said member, a plurality of :adjustable brackets on said supporting member'fa pair'of pivotally mounted arms depending from* ,each of'said brackets-:a flexible rubber;,ibearing connecting said armswith saidbracket a master cam-followeri'rolle'r onone arm of'each pair ofsaid arms, a lapping element on the other arm of each pair of said arms, said rubber bearings being sufficiently flexible so that the arms may rock through predetermined limits, a guide on each of *said brackets .to guidethe follower andilapping arms. supported-thereby; and a Yconnecting link pivotally connected at its opposite ends.

tothefollowerand lapping arms .whereby a controlled rocking movement of the follower arms is. transmitted to, impart a ycontrolled-'rocking movement to saidlapping arms and elements.

13. In acam-lapping machine as claimed in claim '11; inzcombination vwith the parts and features therein specified, of a frame, a pair of Vreciprocable supporting/members, a pair of pivotally mounted-rcckarms .to support said members," flexible rubber :bearingsv connecting said rock arms`with said frame,'flexible rubberbearingsconnecting `,thelower ends of said arm with the' opposite ends-of-said supporting members, l

means to reciprocate said members, a pluralityY of adjustable brackets on each of Asaid supporting members, a pair 'of pivotally mounted arms de'- pending-fromveach 'ofsaid bracketsya flexible rubberv bearing Vconnecting said arms with said brackets, a master cam follower roller on one arm of each -pairof said-arms, a lapping element on the other-armof each pair of said arms, said rubber bearings -beingsuiiiciently flexible so that the arms may rock through predetermined limits, a guideson eachl of said Abrackets to guidethe fol-v lowereand lapping'arms supported thereby, and a connecting link pivotally connected at its olJ- posite ends-to-.the follower and lapping arms whereby `a controlled rockingmovement of the followerearms is transmitted to impart a controlled rockingmovement to said lapping arms and elements.

lll. In a camlapping machine having a base, a pair.-ofupwardly'extending brackets at opposite ends of the base, a pairof vertically arranged arms pivotallysupported on said brackets, a longitudinally reciprocable Work table, pivotal connectionsbetween the opposite ends of said table and' the-lower-ends of said arms whereby `the table maybe reciprocatedin a substantially rectilinear path through a relatively short stroke, flexible rubberbearingsl between said brackets and arms and between'said arms and table, the resil- A ience of said rubber serving-to facilitate a reciptween said arms and table, the resilience of said rubber servingto-facilitate a reciprocatory movementof said vtable,-means including a motor driven:adjustablefcrank'pin which is operatively.

connected. to. reciprocate saidrtable and a pair of vspacedfparallel transversely extending links in-A terposed between `thebase and table, one end of,y

each of. said links beinglconnected by a flexible rubberbearing toltheitable, andthe other end of eachlinkbeing connected by a flexible 4rubber bearing with ther-base, said.Y links and bearings serving. to vguide' and' steadysaid table against trfansverse movement during reciprocation thereo 16; zIna camlapping machine'having a base, a

13 ends of the base, fa pair of vertically arranged arms pivotally supported on said brackets, a longitudinally reciprocable work table, pivotal connections between the opposite ends of said table and the lower ends of said arms whereby the table may be -reciprocated in a substantially rectilinear path through a relatively short stroke, and ilexible rubber bearings connecting said brackets to said arms and said arms to said table, the outer periph'ery of the bearings being xed t0 said arms and the inner periphery of the bearings being xed to the brackets and table respectively, said rubber bearings being sufficiently ilexible so that the arms may swing through predetermined limits.

HERBERT S. INDGE.

REFERENCES CITED The following references are of record in the 5 le of this patent:

UNITED STATES PATENTS Number 

